Impact of initial disease severity and metabolic stress on mortality in patients with suspected external ventricular drain-associated infection.

External ventricular drainage (EVD) remains indispensable for managing intracranial pressure and cerebrospinal fluid (CSF) disorders. Despite advances in neurosurgical care and infection prevention, EVD-related infections still contribute substantially to morbidity and mortality. This study aimed to identify predictors of mortality and evaluate the clinical relevance of infection-related and metabolic parameters in patients with suspected EVD-associated infection undergoing EVD placement. We retrospectively analyzed all adult patients who underwent EVD insertion and were clinically suspected of having an EVD-associated infection at a tertiary hospital over an 18-month period. Data from electronic medical records included demographics, neurological diagnosis, comorbidities, catheter characteristics, laboratory results, and antimicrobial therapy. EVD-associated infection was defined according to Centers for Disease Control and Prevention (CDC) criteria. Statistical analyses were conducted using IBM SPSS Statistics 26. A total of 102 patients with clinically suspected EVD-associated infection were evaluated. CSF cultures were positive in 33 (32%) cases, most frequently yielding Staphylococcus epidermidis and Acinetobacter baumannii . Intensive care unit (ICU) admission was associated with higher crude mortality rates, likely reflecting greater baseline neurological severity. Initial Glasgow Coma Scale (GCS) score (aOR = 0.85, p = 0.005) was found to be an independent predictor of mortality. Neither sex nor comorbidities predicted death. Hyperglycemia (> 140 mg/dL) and elevated lactate (> 1.2 mmol/L) independently associated with 30-day mortality. Shorter catheterization duration (≤ 5 days) also predicted death, likely reflecting greater neurological compromise. In our selected cohort of patients with clinically suspected EVD-associated infection, CSF culture positivity was not independently associated with mortality, although patients with culture-confirmed infection exhibited higher CSF pleocytosis and Cell Index (CI) values. Among patients with clinically suspected EVD-associated infection, initial neurological severity, together with markers of systemic metabolic stress, were independently associated with 30-day mortality. Hyperglycemia and elevated lactate emerged as key prognostic markers. While elevated CI values may support the diagnosis of culture-confirmed infection, CI did not demonstrate independent prognostic value for mortality. These findings should be interpreted within the context of this selected cohort and should not be generalized to the overall EVD population. Larger prospective studies including a greater number of culture-confirmed infections are needed to confirm these results.